HPCC-9777 Document Proxy mode in WsECL

Signed-off-by: JamesDeFabia <James.Defabia@LexisNexis.com>
HPCC-9777 Fixed error made during rebasing

Signed-off-by: JamesDeFabia <James.Defabia@LexisNexis.com>
HPCC-9777 Edits based upon feedback

Signed-off-by: JamesDeFabia <James.Defabia@LexisNexis.com>
HPCC-9777 Fix typo

Signed-off-by: JamesDeFabia <James.Defabia@LexisNexis.com>
Merge pull request #5953 from JamesDeFabia/9777DocProxyOptionWsECLRoxie

HPCC-9777 Document proxy option in WsECL

Reviewed-By: Anthony Fishbeck <anthony.fishbeck@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>